Microorganisms From Some Tropical Fish Diseases

The rotifer Brachionus rotundiformis (total body length 240.59±10.24 μm, lorica length 175.28±9.18 μm, and lorica width 124.28±7.76μm) is commonly used as starter food in the larval rearing of marine fish. But, larvae of some marine tropical fish species required starter food with body size smaller than B. rotundiformis. The present study was aimed to isolate minute rotifers from nature and to assess the possibility of culturing these rotifers. Sampling of rotifers was conducted in an estuary of Mangket (Kema-Minut), using plankton net (mesh size 40 µm). A trial of culturing the rotifers was conducted at salinities of 10, 20 and 30 ppt by using a microalga, Nannochloropsis oculata. A species of rotifer identified as Colurella sp. (family Lepadellidae) was successfully isolated from the sampling location. Body size of Colurella sp. was extremely small (Total length 123.22±5.45 μm, lorica length 95.96±3.81 μm, and lorica width 53.57±3.11 μm), which were smaller than Brachionus rotundiformis SS-type as a conventional starter food for marine fish larvae. Results of culturing the minute rotifer Colurella sp. showed that the species grew well at salinities of 10, 20 and 30 ppt with no significant difference among treatments (ANOVA, p>0.05), indicating a potential use of minute rotifer Colurellasp. as starter food for marine fish larvae. Rotifera Branchionus rotundiformis (ukuran tubuh: panjang total 240,59±10,24 μm, panjang lorika 175,28±9,18 μm, dan lebar lorika 124,28±7,76μm) sering digunakan sebagai pakan awal pemeliharaan larva ikan laut. Namun, larva beberapa spesis ikan laut tropis membutuhkan pakan awal berukuran tubuh lebih kecil dari Branchionus rotundiformis. Penelitian ini bertujuan untuk mendapatkan minute rotifer dari alam (berukuran tubuh lebih kecil dari B. rotundiformis) dan menguji kemungkinan pemeliharaannya. Sampling rotifer dilakukan di perairan estuari Desa Mangket (Kema-Minut), menggunakan plankton net (ukuran mata jaring 40 µm). Uji coba pemeliharaan dilakukan pada salinitas (10, 20, dan 30 ppt) dengan menggunakan Nannochloropsis oculata. Satu spesies minute rotifer yang teridentifikasi sebagai Colurella sp. (family Lepadellidae) berhasil diisolasi dari lokasi sampling. Colurella sp. memiliki ukuran tubuh sangat kecil (panjang total [PT] 123,22±5,45 µm, panjang lorika [PL] 95,96±3,81 µm, dan lebar lorik [LL] 53,57±3,11 µm) yang mana lebih kecil dari Branchionus rotundiformis tipe-SS sebagai pakan awal larva ikan laut. Hasil uji coba pemeliharaan minute rotifer Colurella sp. menunjukkan bahwa spesis ini dapat tumbuh pada salinitas 10, 20, dan 30 ppt dengan perbedaan kepadatan populasi yang tidak signifikan antar perlakuan (Uji ANOVA, p > 0.05) mengindikasikan potensi pemanfaatan minute rotifer Colurella sp. sebagai pakan awal larva ikan laut.

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Studies on Prevailing Parasitic Fish Diseases in Pre-mature Cultured Sea bass, Dicentrarchus labrax, Sea bream and Mugil cephalus at Ismailia, Province with Special References to Control

International Journal of Veterinary Science ◽

10.37422/ijvs/20.075 ◽

2020 ◽

Keyword(s):

Parasitic Infection ◽

Dicentrarchus Labrax ◽

Sea Bass ◽

Mugil Cephalus ◽

Sea Bream ◽

Fish Diseases ◽

Total Prevalence ◽

Dark Colour ◽

Gill Filaments ◽

Mature Fish

This study concentrated on the assessment of the prevailing parasitic fish diseases in some marine fishes at Ismailia province and how to control the infestation using microalgae. This study was carried out on 1080 pre-mature fish (360 D. labrax (225±25 g) and 360 S aurata (150±25 g) and 360 M. cephalus (125±25 g) collected from similar ponds of studies to be examined at the end of treatment. In addition to that we followed non-treated fish (1080 premature). The infested fish showed dark colour and respiratory signs. Post mortem lesions were a presence of congestion or paleness and destruction of gill filaments. The total prevalence of infestation was the total prevalence of parasitic infection of non-treated fishes was 45.83 %. The highest percentage was in D. labrax 56.94 % followed by S. aurata 47.22%, the lowest percentage in M. cephalus 33.33. The total prevalence of parasitic infection in premature treated with 2 g algae was 28.79%, followed by 3 g algae was 23.60 %, while the lowest percentage with 5 g algae was 20.37 % respectively. The detected species of parasites were protozoal parasites, Amyloodinium ocellatum and Riboscyphidia in additions of marine monogenea, Lamellodiscus diplodicus isolated from D Labrex, Mugil Cephalus and S aurata. The present study concluded that, the use of microalgae instead of fish meal decreased parasitic infestation in marine fish. The histopathological alteration of natural infested examined fishes was also recorded.

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Importance of Zebrafish as an efficient research model for the screening of novel therapeutics in neurological disorders

CNS & Neurological Disorders - Drug Targets ◽

10.2174/1871527319666201207211927 ◽

2020 ◽

Vol 19 ◽

Author(s):

Diksha Saluja ◽

Rishabh Jhanji ◽

Swati Kaushal ◽

Bharti Verma ◽

Neelam Sharma ◽

...

Keyword(s):

Animal Model ◽

Neurological Disorders ◽

Tropical Fish ◽

Mammalian Brain ◽

Behavioral Repertoire ◽

Experimental Procedure ◽

Novel Drugs ◽

Associated Functions ◽

Pharmacology And Toxicology ◽

Rats And Mice

Abstract:: In the previous years of research, the use of animal model becomes very common for the screening of novel drugs. Animal model represents the complex problems of humans into simplest forms which can be extended further to include the experimental procedure. The most successful models in neuroscience, rats and mice, undoubtedly considered as one of the best models to understand the psychology of mammalian brain and its associated functions involved in various behavioral repertoire. Moreover, recently researchers in behavioral neuroscience are focusing more on the use of aquatic animals especially fish as model species due to their simplicity, and cost effectiveness. Zebrafish (Danio rerio) is a tropical fish from minnow family a genetic structure surprisingly 84 % similar to humans. It is gaining popularity as a model to study the mechanism in behavioral neuropharmacology. Moreover, Zebrafish is having numerous advantages over other rodent models like ease in maintenance due to their small size; breeding power is more, transparency of embryos, overall reduced cost of experimentation and many more. Nowadays, it is considered as an ideal model to study the neurobehavioral aspects with relevance to humans. It is also used in varieties of scientific studies like genetics, neuroscience, pharmacology, and toxicology. In this manuscript, we have described the feasibility and importance of Zebrafish as a model for the screening of novel drugs for different neurological disorders.

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Shared jurisdiction between veterinarians and aqua medicine biologists in fish health—a Norwegian model for inter-professional and cross-sectoral collaboration

Review of Agricultural Food and Environmental Studies ◽

10.1007/s41130-020-00118-8 ◽

2020 ◽

Author(s):

Wenche M. Kjæmpenes

Keyword(s):

Scientific Knowledge ◽

Disease Outbreaks ◽

Early Response ◽

Marine Science ◽

Fish Health ◽

Fish Diseases ◽

Aquaculture Industry ◽

The Right ◽

The University ◽

Key Events

Abstract This article investigates, using a sociology of profession approach, why veterinarians and aqua medicine biologists share jurisdiction in fish health in Norway. I use a five-actor framework to highlight key events in the development of the Norwegian model for inter-professional and cross-sectoral collaboration in fish health. Veterinarians were initially the only profession involved in fish health. However, in the late 1980s, the Norwegian aquaculture industry suffered great losses due to significant disease outbreaks. Lack of scientific knowledge about the disease causing the outbreaks, Hitra disease, and lack of veterinary capacity to cope with the problem resulted in a situation in which veterinarians continued, as an early response to the disease, to use antibiotic-based therapies. The marine science milieu, with support from the aquaculture industry, instituted a vaccine solution to the endemic Hitra disease in 1987. This scientific breakthrough had major impacts on combatting fish diseases and on the further development of vaccines. New vaccine solutions for other diseases, such as furunculosis, were developed by international and multidisciplinary collaboration. Over a 7-year period, the use of antibiotic-based therapy was dramatically reduced. The control of fish diseases is aquaculture’s X factor, and without these vaccine solutions and regulation regimes, the story of Norwegian aquaculture could have been different. The successful development of the Hitra disease vaccine enabled the marine science milieu at the University of Bergen and the University of Tromsø to establish a new programme of education for aqua medicine biologists based on their own scientific knowledge base. However, their struggle for shared jurisdiction, including the right to prescribe veterinary medicine, lasted nearly 20 years. In 2005, veterinary legislation was amended, and in addition to medical doctors, dentists and veterinarians, aqua medicine biologists, as the fourth profession in Norway, gained the right to prescribe medical products. I argue that the experience in Norway, where professionals from two different sectors share jurisdiction and work side by side in fish health, is worth examining as a model for organizing inter-professional and cross-sectoral collaboration.

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Predicting range-shift success potential for tropical marine fishes using external morphology

Biology Letters ◽

10.1098/rsbl.2016.0505 ◽

2016 ◽

Vol 12 (9) ◽

pp. 20160505 ◽

Cited By ~ 9

Author(s):

Shannen M. Smith ◽

Rebecca J. Fox ◽

Jennifer M. Donelson ◽

Megan L. Head ◽

David J. Booth

Keyword(s):

Fish Larvae ◽

Climatic Conditions ◽

Invasion Success ◽

Range Shift ◽

Tropical Fish ◽

Range Shifts ◽

Native Community ◽

The Family ◽

Moorish Idol ◽

New Habitats

With global change accelerating the rate of species' range shifts, predicting which are most likely to establish viable populations in their new habitats is key to understanding how biological systems will respond. Annually, in Australia, tropical fish larvae from the Great Barrier Reef (GBR) are transported south via the East Australian Current (EAC), settling into temperate coastal habitats for the summer period, before experiencing near-100% mortality in winter. However, within 10 years, predicted winter ocean temperatures for the southeast coast of Australia will remain high enough for more of these so-called ‘tropical vagrants’ to survive over winter. We used a method of morphological niche analysis, previously shown to be an effective predictor of invasion success by fishes, to project which vagrants have the greatest likelihood of undergoing successful range shifts under these new climatic conditions. We find that species from the family of butterflyfishes (Chaetodontidae), and the moorish idol, Zanclus cornutus , are most likely to be able to exploit new niches within the ecosystem once physiological barriers to overwintering by tropical vagrant species are removed. Overall, the position of vagrants within the morphospace was strongly skewed, suggesting that impending competitive pressures may impact disproportionately on particular parts of the native community.

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